Overview of Minerals

Six macrominerals are required by people in gram amounts.

• Four cations: Sodium, potassium, calcium, and magnesium

• Two accompanying anions: Chloride and phosphorus

Daily requirements range from 0.3 to 2.0 g. Bone, muscle, heart, and brain function depend on these macrominerals.

(See also Water and Sodium Balance.)

Nine trace minerals (microminerals) are required by people in minute amounts:

• Chromium

• Copper

• Fluorine

• Iodine

• Iron

• Manganese

• Molybdenum

• Selenium

• Zinc

Dietary guidelines for trace minerals have been determined (see table Guidelines for Daily Intake of Trace Minerals). All trace minerals are toxic at high levels; some minerals (chromium) may be carcinogens. It is not clear whether chromium should be considered an essential (required) trace element (1).

Trace mineral deficiencies (except for iodine, iron, and zinc) do not often develop spontaneously in adults on ordinary diets; infants are more vulnerable because their growth is rapid and intake varies.

Trace mineral imbalances can result from hereditary disorders (eg, hemochromatosis, Wilson disease), kidney dialysis, parenteral nutrition, restrictive diets prescribed for people with inborn errors of metabolism, or various popular diet plans.